How it works Import feature?

It imports just one event or can be a multi-event ICS?
It imports the actual content or it imports the new contents added after the inport operation?
It has any sense to import another Gancio instances ICS or any other ICS generator agenda? (I tried with the demo site but it returns a 404 error)

NOTE: I didn’t find this info in the documentation but if there is written information somewhere I’ll apreciate the URL.

Thank you!